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Biomedical subjects

K Takata

Publications and source records attributed to K Takata.

At least 253 records · Page 14Linked to original sources
PubMed1982

Identification and properties of the glucose transporter of human erythrocytes.

Several lines of studies were undertaken to clarify the identity of the glucose transporter of human erythrocytes. Peptide maps of zone 4.5 which is the main component of the purified transporter fraction, were different from those of band 3. Cytochalasin B bound to the purified transporter fraction but not to band 3. Antibody raised against the purified transporter fraction cross-reacted with zone 4.5 and moderately with band 7, but not with other erythrocyte membrane proteins. These results indicate that zone 4.5 is the transporter (or a part of the transporter) and is not a fragment of band 3. With ferritin antibody electron microscopy and freeze-fracture electron microscopy, the glucose transporter were found to evenly distributed in reconstituted liposomes. Further morphological analysis coupled with transport assays showed the distribution of the transporters was random and was satisfactorily fitted to Poisson distribution, indicating reversible association of the transporters does not occur in liposomes and is not necessary for transport activity. This communication summarises our recent studies on identification and properties of the glucose transporter of human erythrocytes. A full account of the studies is published elsewhere (22, 23).

Blood Glucose↗
PubMed1982

[General pharmacology of T-1982, a new cephamycin antibiotic].

General pharmacological studies on T-1982 produced the following results. On central nervous system, subcutaneous injection of T-1982 at dose of 2,000 mg/kg hastened the onset of pentetrazole-induced tonic extensor in mice. T-1982 had no effect on spontaneous motor activity, pentobarbital hypnosis, body temperature or EEG in mice or rabbits, and also did not show motor incoordinate, anticonvulsive or analgesic activity in mice at intravenous doses of 250--1,000 mg/kg or subcutaneous doses of 500--2,000 mg/kg. On motor and sensory nervous systems, no effect of T-1982 was noted on spinal reflex, neuromuscular junction, conduction anesthesia or surface anesthesia in rats or rabbits. On respiratory, cardiovascular and autonomic nervous systems, T-1982 caused transient increase of respiratory rate, slight hypotension and transient increase of femoral blood flow in dogs at intravenous doses of 250--1,000 mg/kg. However, it caused a slight hypertensive tendency in rabbits. Heart rate and ECG in dogs or rabbits, blood pressure response to epinephrine, isoproterenol, acetylcholine or histamine in dogs, nictitating membrane in cats and pupil size in mice were not affected after intravenous injection of T-1982. No effect was found on isolated guinea pig atrium or rabbit descending aorta following T-1982 application. On renal function in rats, T-1982 caused an increase of PSP excretion but had no effect on urine volume or electrolytes excretion at intravenous doses of 250--1,000 mg/kg. T-1982 prolonged bleeding time in mice at intravenous doses of 500--1,000 mg/kg, but did not show hemolytic property and inhibitory activity on blood coagulation or platelet aggregation in vitro experiments. Spontaneous movement and tone of isolated stomach, ileum, colon, uterus, vas deferens or trachea and acetylcholine-, histamine-, nicotine- or barium chloride-induced contraction of ileum were not affected following T-1982 application. Intestinal propulsion of barium meal in mice, gastric secretion and carrageenin-induced edema in rats were not affected after intravenous injection of T-1982. T-1982 increased bile secretion in rats dose-dependently at intravenous doses of 31.3--125 mg/kg. The local irritative activity of T-1982 in rats was slightly milder than cefoxitin and moderately milder than cefmetazole after intradermal injection. In conclusion, these results suggest that T-1982 would not cause any adverse effects at its estimated clinical doses of 10--20 mg/kg (500--1,000 mg/man).

Animals↗
PubMed1981

Serum lipids and lipoproteins in patients with gallstone (relationship between serum lipids and types of stones in roentgenograms and sectional views).

Serum lipids and lipoproteins of gallstone patients were analyzed and compared with lithogenesity of bile and type of stones by roentgenographic and cross-sectional views. Incidences of hypercholesterolemia and triglyceridemia were higher in patients with radiolucent gallstones than with radiopaque stones. Furthermore, an incidence of hypertriglyceridemia was higher in patients with radiolucent solitary stones than with radiolucent multiple stones. The degrees of hyperlipidemia were moderate. Lipoprotein disc electrophoresis of sera of hyperlipidemic patients revealed type IIa, IIb or IV. More solitary and less multiple stones were seen in the hyperlipoproteinemic patients than normolipoproteinemic. Multiple stones with normolipoproteinemia were more accompanied by unsaturated bile (lithogenic index less than 1.0) than those with hyperlipoproteinemia and solitary stones with hyperlipoproteinemia or without. Solitary stones obtained surgically from normolipoproteinemic patients were pure cholesterol, combination or mixed stones, while multiple stones not including pure cholesterol and combination stones with pure cholesterol in the center. Solitary stones in hyperlipoproteinemic patients proved mostly either pure cholesterol or combination stones with pure cholesterol ins the center, while multiple stones containing all types of stones inclusive of a small number of other miscellaneous stones except cholesterol stones. Collectively more mixed and other miscellaneous stones except cholesterol stones, and less pure cholesterol and combination stones with pure cholesterol in the center were shown in normolipidemic patients, and vice versa in hyperlipoproteinemic patients. These results suggested serum lipids and lipoproteins being closely related to the initial precipitation, aggregation of cholesterol crystals and development of cholesterol gallstones through lipid metabolism of the whole body.

Adolescent↗
PubMed1981

Double labeling study of anionic sites and concanavalin A binding sites in monkey macrophages.

Cationized ferritin (CF) binding, and its effect on the concanavalin A (Con A) binding pattern were studied by the double technique in monkey peritoneal macrophages. CF particles formed clumps and were internalized when cells were incubated at 37 degrees C. Such cells were fixed, and the Con A binding sites were visualized by the Con A-horseradish peroxidase (HRP) method. Using the same specimen, the distribution of CF particles and the Con A-HRP product was observed under an electron microscope. The redistribution and internalization of CF particles did not affect the continuous label of the cell surface Con A binding sites. These observations suggest the independent mobility of cell surface anionic sites and Con A binding sites.

Animals↗
PubMed1979

Estrogen-dependent and progesterone-arrested synthesis and secretion of sulfated glycoproteins in luminal epithelia of rat uteri.

1. 35SO4 administered intraperitoneally was specifically incorporated into a glycopeptide component separated by electrophoresis of the glycosaminoglycan fraction prepared from the uterine epithelia (luminal), as well as the uterine fluid of ovariectomized rats treated with estradiol-17 beta, in contrast to the rats without estrogen treatment. 2. The epithelial cells of uteri isolated from estrogen-treated ovariectomized rats incorporated 35SO4 in vitro into at least two macromolecular components. The larger molecular weight component (sodium dodecyl sulfate polyacryl-amide gel electrophoresis and/or gel filtration) labelled with 35S was observed in both the cytosol and particulate fractions, whereas the smaller molecular weight component labelled with 35S was found only in the particulate fraction. 35SO4 was also incorporated into two macromolecular components in the incubation medium, similarly to the particulate fraction. A 35 SO4-labelled glycopeptide similar to that from the epithelial particulate fraction and the incubation medium, and not from the epithelial cytosol fraction. 3. Progesterone, in contrast to estrogen, did not stimulate the sulfated blycoprotein synthesis. Moreover, progesterone administered together with or after estrogen-administration completely arrested the estrogen-dependent synthesis and secretion of the sulfated glycoproteins in the uterine epithelia.

Animals↗